The studio version of the SBS Designs’ Iso-Q2 Advanced Isolator & Focusing Equalizer has now been updated with resettable, detented gain controls making it easier to recall previous settings. Introduced in 2011, the 1U SBS Iso-Q2 has already seen use as a three-band program EQ in live sound for nightclubs, touring DJs, and has lately found its way into recording and mastering studios.

Key to its design philosophy is the way the Iso-Q2 handles its three bands of equalization. The front panel has separate Bass Frequency and Mid-High Frequency sweepable controls that set the exact lower and upper crossover frequencies between the Bass frequency and High frequency equalizer sections on either side of the central Mid-Range equalizer section.

The Low Frequency sweeps from 50Hz to 400Hz while the Mid-High Frequency sweeps from 3.1kHz to 12.6kHz. It gets fun when I figured out that the three, large detented Bass, Mid-Range Gain and Mid-High Gain controls range from off at fully CCW and up to +15 dB of boost at full CW. They are at unity gain position straight up in the 12noon position; essentially reproducing that band of frequencies at whatever level is presented at the input.

For program equalization, it easy to “build up” the spectral “shape” of a mix by defining these three bands with the application of different amounts of boost or cut using the three bands’ gain controls.

However, the SBS Iso-Q2 does not have frequencies or gain amounts silk screened on the front panel and this encourages the engineer to listen to what it sounds like. I liked the smooth operation of these controls and the super clean sound. Probably because it is controlling a large amount of very hear-able frequencies, I also found the Mid-Range Gain level to be a little touchy to set compared to the Bass and Mid-High Gain controls. It seems that the range of boost/cut in the Mid-Range section could be spread out on the control.

Calibration

I wanted to accurately set up the Iso-Q2 for my first use. I set (as a kind of default) all three Gain controls and the Bass Frequency control fully CCW and put the Mid-High Frequency control at full CW. I then passed a 1kHz tone through the unit and obtained unity gain at the output when only the Mid-Range Gain control was set straight up at 12noon. I found little interaction (overlap) of the other controls for this measurement.

It would be a nice touch if there was a way to have this Mid-Range Gain control “click” when at unity–actually I’d be fine with silkscreen marking unity gain on the front panel. The calibrated Mid-Range Gain control (at unity), the Bass Frequency at CCW, the Mid-High Frequency at CW and both the Bass and Mid-High Frequency Gain controls at full CCW or off would be my starting setup whenever I would begin using the ISO-Q2 during a session.

The SBS Iso-Q2 has no hardwire bypass feature so when I connected it to my Pro Tools HDX system’s I/O, I set up two stereo paths (one with the unit in the path and one without) to A/B, with and without, the Iso-Q2′s effect quickly just like when using any other equalizer in the studio.
In The Studio

I tried the Iso-Q2 on full program mixes and individual instrument and vocal stereo tracks in my Pro Tools mixes. I found the unit to be super quiet and noise-free and best suited for overall equalizing of finished mixes, stereo keyboards–pianos and synth pads, orchestral strings, and stereo drum loops. The manual offers several tips for usage along with the approximate knob locations of the Bass and Mid-High frequency points on the front panel.

The Iso-Q2 has balanced XLRs input and output connectors as well as unbalanced inputs and outputs on RCA jacks. There are also RCA jack connections for a selectable unbalanced loop insert path along with a rear panel master gain control.